Last lecture for Microbiology 1!

Today, we continue with lecture on control of microbial growth.

 Effectiveness of antimicrobial treatment depends on:

1. number of microbes

2. duration of exposures.

3. microbial characteristics.

Action of microbial control agents

1. alternation of membrane permeability

2. damage to protein--- attack plasma membrane

3. damage to nucleic acids ---- impact to DNA, affect synthesis of sterol--- affect reaction lipids at cell wall, impact DNA replication, production of amino acids. 

Physical control method:

heat --- filtration --- radiation

Chemical control agents:

Disinfection --- antisepsis --- sterilization

Next, the topic was on Antimicrobial Chemotherapy

Well, actually, this lecture was a little bit fast that I can't really catch up it. And some of the slide, Dr Wan skipped them because she said that it was too detail, so she will upload the one which is more easier to read. 

So today's class was the last class. Here I want to thank Dr Wan a lot for being a very caring, sporting, and supportive lecturer. Dr Wan treat us like we are the only her students. Never neglect us. And always put us as one of her priorities. Thank you a lot for teaching us all those technologies that we never heard before. I will try my best to apply it in next semesters. I am looking forward to the semesters that Dr Wan will be teaching us again. Pray for us Dr hehe. That's all for now. Assalamualaikum :)

Second last lecture!

Microbial growth topic continued.

Here are some definitions:

Culture medium: A nutrient material prepared for the growth of microorganisms in a laboratory.

Inoculum: Microbes that are introduced into a culture medium to initiate growth. 

Culture: The microbes that grow and multiply in on or culture medium.

Sterile: No living organisms. 

And the most interesting part, we have some calculation here! Hehe I've been missing mathematics so much.

The formula is to calculate number of generations and generation time.

Number of generation = log num of cells(end) - log num of cells (beginning)

0.301

Generation time = 60min (hours)

                                num of gen. 

This is Bacterial Growth Curve.

Lag phase: adapt to environment.

Log phase: adapted--start to replicate--use up nutrient--enzyme produced--end product produced.

Stationary phase: maximum sustainability due to deficiency of nutrient--start to reduce growth.

 Death phase: no nutrient left--die

To calculate number of bacteria in direct microscopic count:

Number of bacteria=  number of cells counted

                                    volume of area counted

And on control of microbial growth topic, the frequently used terms are:

Sterilization- removal of a microbial life

Commercial sterilization- killing C. botulinum endospores

Disinfection- Destruction of pathogens

Antisepsis- destruction of pathogens from living tissue

Degerming- removal of microbes from a limited area

Sanitization- lower microbial counts on eating utensils

Biocide/germicide- kills microbes

Bacteriostasis- inhibiting, not killing, microbes

Ok that's all for now.

Hectic week with Dr Wan :D

The topic was on microbial growth. Basically for the first part, it describes the physical and chemical requirements for microbial growth. 

Physical : light, temperature, pH, water activity and osmotic pressure.

Chemical : electron donor, electron acceptor, micronutrients ( vitamins, amino acids, trace minerals)

Next, it was about isolation/culturing, maintaining and preserving microbes.

The steps in aseptic technique are: 

1. Flame all caps and lids

2. Tightly close all caps

3. Remove materials from the hood

4. Turn off gas

5. Wash the hood surface

6. Turn the UV light on to disinfect

Pure culture is a population of identical originating from a single cell.

Sub culture: the process of transferring bacteria from grown culture to new culture (fresh agar).

Methods obtaining pure culture: Streak plate method, pour plate method. 

Special culture techniques: Culture anaerobic organisms.

And the topic was continue on Thursday.

Hi

We started our class with playing a game or quiz I can say. There are 10 questions. And my group, group 10 got 5 correct hehe. Well, out of 10 question, I actually can recall only question, I mean 1 complete question. It is, ‘What is the name of reversible reaction of oxidation and reduction?’ I think it sounds like that but whatever it is, the answer is redox reaction.

And then, Nuaim, Radin, Malik and Syafiq made a presentation on green sulfur bacteria (Chlorobium), green non-sulfur bacteria (Chloroflexus), purple sulfur bacteria (Chromatium) and purple non-sulfur bacteria (Rhodobacteria) and cyanobacteria.

Cyanobacteria – aquatic, bluish pigment, contain chlorophyll a, photoautotroph.

Chromatium – anaerobic, chlorophyll a and b, they need oxygen to live but they can only live in low content of oxygen.

Rhodobacter – can only tolerate small concentration of sulfur

Chlorobium – need sulphide to grow, use H2S, inorganic molecules and H2 as electron donors.

Chloroflexus – photoeteritroph, found in hot spring

Actually the presentation was longer than these, but these are the things that I could catch up at that time hehe.

Okay that’s all!

Microbial Metabolism

Today the lecture was still on microbial metabolism. We continued on this topic a little bit more. There are three types of cellular respiration – aerobic respiration (require oxygen), anaerobic respiration (does not require oxygen)  and fermentation (lactic acid fermentation, alcohol fermentation). The metabolic pathways for aerobic respiration are glycolysis, transition reactions, citric acid cycle and ETC& chemiosmosis.

Photosynthesis is the process where light energy is captured to synthesize ATP, NADH or NADPH. Prokaryotic organisms that undergoes this process are green sulfur bacteria (Chlorobium), green non-sulfur bacteria (Chloroflexus), purple sulfur bacteria (Chromatium) and purple non-sulfur bacteria (Rhodobacteria) and cyanobacteria.

Carbon fixation is the process where CO2 is converted into inorganic form. The most common pathway for this process is Calvin Cycle.

Then we continue with nutritional types of microorganisms.

What I like about this topic is, from the name you get all the information without even have to memorize it.

ENERGY SOURCES

Photo = light

Chemo = organic/inorganic compounds

CARBON SOURCES

Auto = self feeders

Hetero = feeders on others

ELECTRON SOURCES

Litho = inorganic

Organo = organic

So basically if the type of nutrition is photoorganoheterotroph – it means, light is the energy source, organic C molecules is the carbon source and organic molecules is the electron source. Easy isn’t?

One more is mixotroph. It alter metabolic patterns in response to environmental changes. Which means it may use either light or organic/inorganic compounds as energy sources.

For the next class, there will be a bit explanation on green sulfur bacteria (Chlorobium), green non-sulfur bacteria (Chloroflexus), purple sulfur bacteria (Chromatium) and purple non-sulfur bacteria (Rhodobacteria) and cyanobacteria.  I will update it later!

Yakult!

We went to Yakult factory and we listened to a brief explanation about Yakult by their representative.  So I will share here a little bit what we get there. Yakult is basically a pioneer in the field of probiotic. Yakult contains Lactobacillus casei shirota (popularly known as Shirota strain). Shirota strain is scientifically proven to be among the strongest strain as it can survive in gastric juice and bile juice. This Shirota strain reaches the intestines alive, so this product maintains good health by increasing beneficial bacteria, decreasing harmful bacteria and improving the intestinal environment.  It is free from preservatives, colourings and stabilizers and that is why, Yakult only have 1 flavour. 

There is no maximum number of bottles of Yakult that one can drink per day. But 1-2 bottles per day is okay.  It is not a problem to keep yakult outside of the fridge for awhile. Yakult bacteria slowly become active at the range temperature of 15 to 40 degree celcius. When the bacteria become active, it will produce lactic acid thus making Yaklut taste sour. However that is not a problem to drink it.

How to make Yakult?

1.       Mixing of raw ingredients

2 .       Sterilization

3.       Culture tank- temperature of tank is 37 degree celcius and Shirota strain is added.

4.       Mixing and storage tank – temperature is 2 degree celcius.

5.       Injection blow moulding machine – bottles are made from polystyrene

6.       Bottling and packaging

7.       Refrigeration room – finished products are kept refrigerated

This factory which located in Seremban, Negeri Sembilan, is a small factory I can say. But with modern technology and machines, they can produce thousands of Yakult per day. And I can only see few workers. Well the positive side is we know we are getting more modern now and without many workers there, the possibility for Yakult to get contaminated or whatever is less. But the negative side is, this is one of the reasons why many people are unemployed.

Here is the group photo of us there :D

Quiz timeeeeeeeee

Based on the title, I will only talk about the quiz we were playing earlier today hahaha. Because I really love the quizzes we played together. 

These are the flashcards that we created on quizlets.

What so interesting about this quizlet is, from the terms and definition we create on the f;ashcards there,we can also play the terms in form of test, learn, scatter and even in a game called space race!

It took  just a little effort to complete the flashcards and turns out to be more effective ways of learning. 

These are some of terms I include in the flashcards.

We also played few quiz together created by ourselves of course hehe. There were socrative, kahoot and proprof. As my group created the quiz using kahoot, I am going to show to you kahoot only.

 You can just join in at kahoot.it, but the most interesting way to play it is play with classmates. The more the merrier!

 The creator will conduct the whole quiz. Interesting isn't? Sometimes, I really do hope someone actually read my blog because I think I share almost every new things Dr Wan taught us. So that the readers also get the chance to try it because it really benefit us.

Till, then. Thank you again Dr!

Mighty Microbe Game!

Today class was a replacement class. And it was 3 hours lecture!

From 11 am - 2 pm.

Everything went well because from 12-1pm, we played a game which named, Mighty Microbe. The game is nearly the same with UNO game, but there are some modification. For example, we must say the name of microbe written on the card. There are also parasitism and mutualism cards. And few mighty cards. Luckily there are no questions that have to be answered hehehehe.

Basically we played the game because during that time, some of my classmates must attend their BBI class. Here are some of the pictures of us playing the game (but I'm not in the picture).

And here is the picture of cake Dr Wan bought for us hehehehe :D

Well actually we continued our class as usual, but this game was what attract me more haha. I think this is a good game eventho it seems like similar to UNO game. And for me, when we get the mighty draw card, it should have question to be answered there. It doesn't matter if the player have to google or ask other people, as long as they answer it. So I think that it is not necessary for the positive or negative card. Whatever it is, this is just my opinion. 

And this is the questions that I have told before, the questions that Dr Wan gave us. I have answered it. But don't know whether it is correct or wrong.

I guess that's all for today. Thank you Dr Wan! :D

Nomenclature

Hi. It has been a while since the last time I update this blog( it is only a week anyways hehe)

So we continue our class with Dr Wan again yeay. 

The topic was on Nomenclature.

This post will surely be a very short post as the class was only an hour lecture.

Nomenclature: Assignment of names to taxonomic groups in agreement with published rules
 

It is defined by two names. Called the binomial nomenclature   
   • Genus name + specific epithet (species)   
  

General Rules:

1.  Genus name always capitalized (e.g. Escherichia)

2.  Species name is never capitalised (e.g. coli)

 3.  Species name is never used without the genus name (e.g. coli standing alone) 

4.   Genus name may be used without species name (e.g. Escherichia) 

5.  Genus and species are always italicized (or underlined)

6.   First time -- spell out (Escherichia coli), thereafter -- abbreviated (E. coli)

 7.   Species name -- never abbreviated 

8.   Less simple genus abbreviation if different genus start with same alphabet.    e.g. Enterococcus faecalis (En. faecalis)    Escherichia coli (Es. coli) 

Dr Wan did assign us with some simple questions for us to answer. I will include it in my next update. That's all for now!